/*
 * Copyright 2009-2011 Cedric Priscal
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <termios.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <jni.h>

#include "SerialPort.h"

#include "android/log.h"
static const char *TAG="serial_port";

static speed_t getBaudrate(jint baudrate)
{
	switch(baudrate) {
		case 0: return B0;
		case 50: return B50;
		case 75: return B75;
		case 110: return B110;
		case 134: return B134;
		case 150: return B150;
		case 200: return B200;
		case 300: return B300;
		case 600: return B600;
		case 1200: return B1200;
		case 1800: return B1800;
		case 2400: return B2400;
		case 4800: return B4800;
		case 9600: return B9600;
		case 19200: return B19200;
		case 38400: return B38400;
		case 57600: return B57600;
		case 115200: return B115200;
		case 230400: return B230400;
		case 460800: return B460800;
		case 500000: return B500000;
		case 576000: return B576000;
		case 921600: return B921600;
		case 1000000: return B1000000;
		case 1152000: return B1152000;
		case 1500000: return B1500000;
		case 2000000: return B2000000;
		case 2500000: return B2500000;
		case 3000000: return B3000000;
		case 3500000: return B3500000;
		case 4000000: return B4000000;
		default: return -1;
	}
}

static void throwException(JNIEnv *env, const char *name, const char *msg)
{
	jclass cls = (*env)->FindClass(env, name);
	/* if cls is NULL, an exception has already been thrown */
	if (cls != NULL) {
		(*env)->ThrowNew(env, cls, msg);
	}

	/* free the local ref */
	(*env)->DeleteLocalRef(env, cls);
}

/*
 * Class:     android_serialport_SerialPort
 * Method:    open
 * Signature: (Ljava/lang/String;II)Ljava/io/FileDescriptor;
 */
JNIEXPORT jobject JNICALL Java_android_1serialport_1api_SerialPort_open
		(JNIEnv *env, jclass thiz, jstring path, jint baudrate, jint parity, jint dataBits, jint stopBit)
{
	int fd;
	int flags;
	speed_t speed;
	jobject mFileDescriptor;
	flags=0;
	/* Check arguments */
	{
		speed = getBaudrate(baudrate);
		if (speed == -1) {
			throwException(env, "java/lang/IllegalArgumentException", "Invalid baudrate");
			return NULL;
		}
		if (parity <0 || parity>2) {
			throwException(env, "java/lang/IllegalArgumentException", "Invalid parity");
			return NULL;
		}
		if (dataBits <5 || dataBits>8) {
			throwException(env, "java/lang/IllegalArgumentException", "Invalid dataBits");
			return NULL;
		}
		if (stopBit <1 || stopBit>2) {
			throwException(env, "java/lang/IllegalArgumentException", "Invalid stopBit");
			return NULL;
		}
	}

	/* Opening device */
	{
		jboolean iscopy;
		const char *path_utf = (*env)->GetStringUTFChars(env, path, &iscopy);
		fd = open(path_utf, O_RDWR | flags);
		(*env)->ReleaseStringUTFChars(env, path, path_utf);
		if (fd == -1)
		{
			throwException(env, "java/io/IOException", "Cannot open port");
			return NULL;
		}
	}

	/* Configure device */
	{
		struct termios cfg;
		if (tcgetattr(fd, &cfg))
		{
			close(fd);
			throwException(env, "java/io/IOException", "tcgetattr() failed");
			return NULL;
		}

		cfmakeraw(&cfg);
		cfsetispeed(&cfg, speed);
		cfsetospeed(&cfg, speed);

		/* More attribute set */
		switch (parity) {
			case 0: break;
			case 1: cfg.c_cflag |= PARENB; break;
			case 2: cfg.c_cflag &= ~PARODD; break;
		}
		switch (dataBits) {
			case 5: cfg.c_cflag |= CS5; break;
			case 6: cfg.c_cflag |= CS6; break;
			case 7: cfg.c_cflag |= CS7; break;
			case 8: cfg.c_cflag |= CS8; break;
		}
		switch (stopBit) {
			case 1: cfg.c_cflag &= ~CSTOPB; break;
			case 2: cfg.c_cflag |= CSTOPB; break;
		}
		int rc = tcsetattr(fd, TCSANOW, &cfg);
		/*
        if (rc)
        {
            close(fd);
            throwException(env, "java/io/IOException", strcat("tcsetattr() failed: ", rc));
            return NULL;
        }
        */
	}

	/* Create a corresponding file descriptor */
	{
		jclass cFileDescriptor = (*env)->FindClass(env, "java/io/FileDescriptor");
		jmethodID iFileDescriptor = (*env)->GetMethodID(env, cFileDescriptor, "<init>", "()V");
		jfieldID descriptorID = (*env)->GetFieldID(env, cFileDescriptor, "descriptor", "I");
		mFileDescriptor = (*env)->NewObject(env, cFileDescriptor, iFileDescriptor);
		(*env)->SetIntField(env, mFileDescriptor, descriptorID, (jint)fd);
	}

	return mFileDescriptor;
}

/*
 * Class:     cedric_serial_SerialPort
 * Method:    close
 * Signature: ()V
 */
JNIEXPORT void JNICALL Java_android_1serialport_1api_SerialPort_close
		(JNIEnv *env, jobject thiz)
{
	jclass SerialPortClass = (*env)->GetObjectClass(env, thiz);
	jclass FileDescriptorClass = (*env)->FindClass(env, "java/io/FileDescriptor");

	jfieldID mFdID = (*env)->GetFieldID(env, SerialPortClass, "mFd", "Ljava/io/FileDescriptor;");
	jfieldID descriptorID = (*env)->GetFieldID(env, FileDescriptorClass, "descriptor", "I");

	jobject mFd = (*env)->GetObjectField(env, thiz, mFdID);
	jint descriptor = (*env)->GetIntField(env, mFd, descriptorID);

	close(descriptor);
}